The present invention relates to improvements in fuel dispenser electronics design. More particularly, the present invention provides a local operating network for a fuel dispenser to permit modular design and construction with minimal wiring and no unused components.
Modem fuel dispensers use microelectronics to assist in carrying out the dispenser's functions of pumping and dispensing fuel, recording the amount sold, and providing, in some cases, convenient credit or debit card payment options. Often, these latter features have been add-ons to pre-existing dispenser designs, with the result that the dispenser interior may have extensive wiring and cabling for power and control signals, which promotes the possibility of various errors occurring. Usually, a single microprocessor has primary dispenser control, as seen in dispenser 10 in FIG. 1. Cabling and wiring emanates from a central microprocessor 26. The central microprocessor 26 may be of the model known as Z80.
Many modem dispensers can be approached from two sides, each by a customer fueling his or her vehicle, so dispensers include side A and side B capabilities to service these customers. The wiring and cable emanating from the microprocessor 26 includes hardware I/O cable 13 leading to side A main display 12 and its associated price posting units 14. The hardware I/O line 13 also leads to side B main display 16 and its price posting units 18. Power to the microprocessor 26 is obtained through an AC input 20 fed through a power supply 22 and a main regulator 24 to provided a regulated DC supply along line 28.
Some dispensers have a programmable pump preset, which turns the pump off after a certain amount of fuel has been dispensed. In dispensers of this type, a preset 30, often a Z80 microprocessor, has a serial interface 32 to the microprocessor 26.
The microprocessor 26 also receives data along the hardware I/O line 34 from a manager keypad 36. The manager keypad is a small keyboard located inside the electronics portion of the dispenser. It is used for pump programming and certain diagnostic functions. Access to this keypad is restricted to authorized personnel via a locked door and provides up to three levels of security codes. Accordingly, the information communicated along line 34 can be quite complex.
The microprocessor 26 also receives data from the hardware I/O line 42 from a hydraulic interface 40 which, in turn, has wiring and cabling to a number of spaced-apart units 38 including pump handles, submerged turbine pumps, valves and the pulsers of the dispenser. The pump handles are the units on the outside of the dispenser on which nozzles usually rest and which are raised by the customer to indicate that fuel is to be dispensed. The submerged turbine pumps are located, typically, in underground storage tanks at the end of a supply conduits and actually provides the function of forcing the fuel to be dispensed through the supply conduits and the dispenser. The various valves involved control the flow of the liquid as required. Pulsers are known units in fuel dispensers. Pulsers are connected to meters which are forced to rotate by the flowing fuel. The rotation of the meter drives the pulser to output electrical pulses corresponding to the volume of liquid being dispensed. Typically, each pulse represents one/one-thousandths of a gallon. The foregoing description applies to the multi-product dispensers, which are now commonplace. Not shown in FIG. 1 is the possibility of a different hydraulic interface 40 and series of pumps and valves 38. If the dispenser is a blending dispenser such as is shown in U.S. Pat. No. 5,029,100 to Young et al.; U.S. Pat. No. 4,876,653 to McSpadden et al.; or U.S. Pat. No. 4,978,029 to Furrow et al., all owned by Gilbarco, the assignee of this application, a different control configuration to cause different grades of fuel to be blended as they are dispersed will be desired. The entire disclosure of these patents is incorporated herein by reference.
Also as seen in FIG. 1, the microprocessor 26 has a two-wire connection 46 to additional devices in some embodiments. Thus, as shown in FIG. 1, a side A card reader in dispenser (CRIND) logic module 44 is connected to card reader peripherals 48. The peripherals may include a card reader for reading the magnetic stripe on a credit or debit card, a printer to print receipts, a display associated with the card reading and printing process, and a note or currency acceptor for receiving currency. Other types of payment arrangements can also be used, such as the debit card arrangement disclosed in U.S. patent application Ser. No. 08/160,936, now abandoned filed Dec. 2, 1993, of Kaehler, the entire disclosure which is hereby incorporated by reference. Side B card reader logic module 50 and side B card reader peripherals 52 are also provided, similar to Side A.
Typically, the card reader logic module 44 will have communications capability over a line, such as a twisted pair 54 to a service station site controller. This is necessary in order to validate credit cards, and the like. In this regard, the communication may be encrypted, as disclosed in U.S. Pat. No. 5,228,084 of Johnson et al., entitled "Security Apparatus and System for Retail Environments", the entire disclosure of which is incorporated herein by reference. Similarly, card reader and personal identification number input devices and protocols as described in U.S. Pat. No. 4,967,366 of Kaehler entitled "Integrated Gasoline Dispenser and POS Authorization system with Unattended PIN Pad" may be used, and the disclosure of that patent is incorporated herein by reference.
The net effect, as seen in FIG. 1, is that the microprocessor 26 has numerous inputs and communication capabilities to the various components of the dispenser 10. As the central hub, the processor 26 monitors many inputs and controls many outputs. It is also responsible for many internal operation controls and calculations. This design suffers a limitation on the number and kind of feature options such as the displays, card readers and printers that can be added to and controlled by the single computing element. Also, by having each component tie back to the central processor, the number of cables required in dispensers increases, and it also adds to the level and complexity required in the microprocessor 26. This is further complicated by the need to supply power to the devices, such additional power supply wiring connections are not shown in FIG. 1.
The manufacture of such a dispenser requires careful attention to detail to properly assemble wiring harnesses and connections. The cabling is time-consuming, and errors can easily occur. Therefore, there is a need in the art for an improved dispenser electronics design to minimize the number and complexity of wiring connections.